Electromagnetic fluid pump



PHD-11 KR 22669l83 Feb. 16, 1954 I I N. H. GODBOLD Filed Feb. 27. 1951 ELECTROMAGNETIC FLUID PUMP 2 Sheets-Sheet 1 INVENTOR. Nat H. Gadbo/d BY Feb: 16, 1954 Filed Feb. 27, 1951 N- H. GODBOL ELECTROMAGNETIC FLUID PUMP 2 Sheets-Sheet 2 W/Tgf"w WW INVENTOR.

Naf H. Godbo/d Patented Feb. is, less UNITED STATES. PATENT OFFICE sumousgyh'icrwmruur Natl. cos

bolaLIdahe I'alh, Idaho, a-ignor to the United Stat. of America as by theUnited States Atomic Energy represented Commi- Application February 27,1951, Serial No. 212,!

This invention is related to that disclosed in application Serial No. 182.121 flled Au u 29'. 1950. by Nat H. Godbold. and is an improvement in electromagnetic fluid pumps of the type described therein.

Electromagnetic fluid pumps of the type which a conducting fluid is impelled along a channel by the reaction of a transverse current throughthefluidandanimpressedfleldare generally old, as shown for example, in Patents 2,397,785 and 1,298,644 to l'reidlander and Chubb.

art devices utilize directly the force resulting een the electric current in the fluid and the impressed magnetic fleld ior causing movement of the fluid and this eflect is not sufllcient to create the pressure or volume of flow required for many purposes.

The referenced parent application 182.121 discloses a novel arrangement of an electromagnetic fluid pump of greatly improved performance over prior art devices. This is accomplished by an arrangement somewhat similar to the induction motor. The magnetic structure comprises the stator-of an induction motor and a locked rotor with a fluid channel space between the stator and rotor. The fleld is energized with a rotating magnetic fleld so that fluid in the channel has induced in it, by the rotating magnetic fleld. electric currents which react in the usual manner with the rotating magnetic fleld to cause rotation of the fluid. In this way, kinetic energy is accumulated in the fluid during the passage of the fluid longitudinally through the channel so that a high angular velocity is present in the fluid by the time the exhaust port is reached. The rotational momentum of the fluid is readily translated into linear momentum by centrifugal force causing a practical pressure and volume of flow.

The present invention is directed to an improved magnetic and fluid channel structure in which the induction motor principle is utilised in a manner which results in enhanced fluid pressure and flow.

Other features and advantages not particularly enumerated will become apparent from further consideration of the speciflcation which includes the drawing; and the appended claims.

In the drawing:

Figure l is a'longitudinal cross section of an electromagnetic fluid pump embodyin this invention.

l'lguresisadiametricalcrosssectionoithe fluidpumpotl'lgureltakenontheplane {-4 5 Claims. (.0!- 108-1) section or Figure l.

Referrlngtothedrawin'g,l'lguresland2,one preferred manner or practicing the concept of this invention is shown in diagrammatic form. Thenmneralsland ii designateouterandlnner magnetic structures which together constitute the stator. For convenience in expression, the outer member! is hereinafter entitled the fleld envelope and the inner member I l is entitled-the fleld core.-

The fleld envelope 0 comprises a laminated iron structure it having a circular internal surface and'slots II for housing electric windings ii. A metal band or canister it surrounds the fleld laminationsiosupporttheminplaceinarlgld assembly. A plurality of magnetically permeable and non-magnetic rings II. and II, respectively, are arranged in alternate sequence in the interior of the laminated structure II. These rings are right triangles in cross section and one each of the permeable rings and the non-magnetic rings are juxtaposed with the sides adjacent the right angles in contiguous relation. It follows that the hypotenuses oi the rings form a plurality of alternate converging and diverging surfaces. Each diverging surface is the boundary of a magnetically permeable ring I! and each converging surface is the boundary of a nonmagnetic ring II.

The field core comprises a plurality of magnetically permeable triangular-shaped rings 2|, each. having a cross section similar in shape to a composite fleld envelope ring. The fleld core rings are positioned so as to nest with the fleld envelope rings with a space therebetween equal to the desired fluid channel thickness.

The fluid channel comprises an electrically conducting tube 23, a bell-shaped passage ll, and the zi zag passa e between the fleld envelope and fleld core. The tubular channel portion is positioned centrally of the fleld core and merges at the exit end into the central part of the bellshaped channel portion. The outer part oi the bell-shaped portion merges with the flrst diverging passage portion between the fleld envelop and fleld core.

It' has been found to be desirable to impress the rotating magnetic fleld across at least a part of the bellshaped channel and, to this end, the fleld envelope includes magnetic material overhang I1 and the core structure includes permeable cap portions 2! which may be of laminated or DOW- deredironstructure.

The magnetically permeable fleld envelope rings ll andfthe non-magnetic fleld envelope aeeaiss 3 ringsli resultinamuchgreatermagnltudeof magnetic flux cross the diverging fluid channel portion than across the convergin portions of the fluid channel portions.

The eflect of this structure is best explained with reference to Figure 3. The bell-shaped channel portion is traversed by rotating magnetic flux designated by the vector indicators m. The fluid is eiiectiveiy dragged by the rotating held so that the fluid acquires a rotational motion. The centrifugal force acting on the rotating fluid in the diverging channel portion 8| acts in the direction shown by vector 1" and causes the fluid to flow longitudinally over into conver ing channel portion 32. The fluid channel portion I! is not acted upon by the magnetic fleld to anywhere near the extent of the interaction in channel portion a as a consequence of the non-magnetic ring II. It follows as a result of the fluid in channel portion 32 slowing down in angular velocity a slight amount due to frictionallosses that the fluid in channel portion 82 has a smaller integrated centrifugal force than that in channel portion Ii. Accordingly, the fluid although rotating in a plane normal to the longitudinal axis or the pump. also has a motion generally longitudinal of the pump so that it flows out of diverging channel portion 3! into and through converging channel portion 12 and from thence into the next succeeding diverging channel portion 33. The fluid entering diverging channel portion it obviously has a higher rotational velocity than it had when it entered diverging channel portion II. The fluid acquires another increment of rotational velocity in channel portion 33 and in each succeeding diverging channel portion until the terminal exhaust port Ii is reached.

The induced currents in the fluid may circulate through portions of the adJacent metallic structure, but in order to provide a low resistance path. the end diverging channel and exhaust port 35 is electrically connected to the inlet end of tube 23 by conducting ring 88.

While there has been herein described what is at present considered to be a preferred embodiment of this invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention and, it is therefore intended that the appended claims cover all such changes and variations as are embraced within the spirit and scope of the invention.

What is claimed is:

1. An electromagnetic fluid pump for generating an impelling pressure on a conducting fluid comprising a magnetic core structure, and a fluid channel; said fluid channel having an inlet and an outlet end. said magnetic core structure comprising a field envelope and a field core, said fleld core being elongated and of closed geometric configuration in the direction normal to the elongation thereof and being bounded on the outside in the direction of elongation by a plurality of surfaces which alternately diverge and converge with respect to the channel inlet end, said fleld envelope having amagnetic material shell, winding slots in the magnetic material shell parallel to the elongation thereof. and polyphase electric windings threading the winding slots thereof, said fleld envelope having on the interior thereof a plurality of composite rings supported in adjacent relation, each of said composite rings being triangular in cross section and being composed of a magnetic material ring juxtaposed with s non-magnetic material ring and being orientated so that the non-magnetic material ring is adjacent a channel portion which converges with respect to the inlet end; said field core being supported internally within said fleld envelope with the respective opposed surfaces in parallel relation and with a space therebetween to deflne the fluid channel, means electrically connecting the channel inlet end to the channel outlet end whereby under a condition of polyphase excitation of said wlnding a rotating magnetic fleld having radial components or magnetic flux is generated and a greater magnetic flux traverses all the channel portions having a similar inclination and being bounded by magnetic material than the channel portions having the opposite inclination and which are bounded at least in part by non-magnetic material, means for admitting fluid into the channel inlet end and means for exhausting fluid from said fluid channel outlet end.

2. An electromagnetic fluid pump comprising amagneticstructurehavingaflrstandasecond fleld core element, a polyphase electric winding. and a fluid channel; said fluid channel having an inlet end and an outlet end, said flrst fleld core element being, of elongated annular shape and supporting internally thereof alternately juxtaposed magnetic and non-magnetic material rings with the non-magnetic ring of each pair of rings being on the side more closely adjacent than the magnetic ring on the channel inlet end, said rings being right triangular in cross sectional shape and juxtaposed in pairs with the right angles of the rings in each pair being adjacent to each other whereby the interior surface of the flrst fleld core element is zi z in the direction of the elongation thereof and circular normal to the elongation, said second fleld core element having on a circumferential surface a plurality of magnetic material rings having a cross sectional shape approximately similar to each pair of flrst fleld core magnetic and non-magnetic rings, said second fleld core element rings being supported in nested relation to the flrst field core element rings with a space therebetween for deflning a fluid channel having channel portions which alternately diverge and converge with respect to the fluid channel inlet end. said electric winding being supported in longitudinal slots in said flrst fleld core element whereby under a condition of polyphase excitation of said electric winding the channel portions bounded on one side by the flrst fleld core element magnetic rings are traversed by a rotating magnetic iield having a radial component, means external of the fluid channel electrically connecting togethertheinletendandtheoutletendofthe fluid channel, and means for admitting conductingfluidintotbesmallendoftheflrstofsaid channel portions and means for exhausting said conductingfluidfromthelargeendofthelast of said channel portions.

3. An electromagnetic fluid pump comprising an alternating current magnetic structure and a fluid channel. said fluid channel having an inlet end and an outlet end, said magnetic structure comprising an outer annular magnetic memher having an inner surface of cylindrical shape, a series of rings of right triangular cross section having an outer diameter approximately equal to that of the inner surface of the outer magnetic member, said rings being alternately of non-magnetic and magnetic material and disposedinpairswithtberishtangleofanonmagnetic ring adjacent the right angle of a magnetic ring and with the bases of the rings supported adjacent the inner surface of the outer magnetic member, said non-magnetic ring of each pair of rings being closer to the inlet end of said fluid channel than the magnetic ring of the said pair of rings, an inner magnetic member of generally annular shape having an outer surface similar to thainner surface of the assembled non-magnetic and magnetic rings and spaced therefrom by the width of the fluid channel, an electrical connection from the outlet end of the fluid channel to the inlet end of the fluid channel and means for generating in the magnetic members and the fluid channel a rotating magnetic fleld having radial components of flux and having its axis of rotation coincident with the axis of the magnetic members, whereby the fluid channel portions adjacent each magnetic ring are traversed with a higher density of rotating magnetic fleld than the channel portions adjacent the non-magnetic material.

4. An electromagnetic fluid pump for creating an impelling force on a conducting fluid comprising an annular fluid channel having an inlet end and an outlet end, said channel being of substantially uniform cross section and having channel portions. which relative to the channel inlet end, alternately diverge and converge, said diverging and converging channel portions being supported in close magnetic coupling and loose magnetic coupling respectively with a magnetic fleld structure, means for generating a rotating magnetic fleld having radial components of magnetic flux and having its axis of rotation coincident with the axis of the fluid channel in said magnetic structure to thereby traverse the fluid channel diverging portions with a stronger magnetic fleld than the fleld which traverses the converging channel portions, means electrically 40 connecting the outlet end of said fluid channel with the inlet end of the fluid channel.

5. An electromagnetic fluid pump comprising an annular magnetic structure supporting thereon a polyphase electrical winding for generating a rotating magnetic fleld having radial components in said magnetic structure and a fluid duct having an inlet end and an outlet end, said fluid duct being supported in said magnetic structure and having a plurality of annular portions which have their axes coincident with the axis of the magnetic structure and which alternately diverge and converge relative to the duct inlet end, the flrst and last fluid duct portions being diverging. all said diverging duct portions being supported in close proximity to the adjacent magnetic structure and said converging duct portions being bounded on at least one side with non-magnetic material, the inlet andv outlet ends of the duct being electrically connected together to provide closing P ths for electrical currents induced in the fluid, whereby electrical currents induced in the fluid interact with the rotating magnetic fleld to impart a greater torque on the fluid in the diverging duct portions than on the fluid in the converging duct portions to cause migration of the fluid from the inlet end of the duct to. the outlet end thereof due to pressure generated by centrifugal force.

NAT H. GODBOID.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name V Date 1,298,664 Chubb Apr. 1, 1919 2,397,785 Friedlander Apr. 2, i946 2.524.269 Patterson Oct. 3, 1950 FOREIGN PATENTS Number Country Date 239,816 Switzerland Mar. 1, 1946 

